The subject matter herein relates generally to electrical connectors and more particularly, to coaxial connectors that are configured to have a predetermined impedance.
In some connector assemblies in which two connectors mate with each other, it is desirable to match impedances of the two connectors to reduce unwanted signal reflections. For example, Bayonet Neill-Concelman (BNC) connectors are typically offered as having impedances with 50 ohms or 75 ohms. The conventional 50-ohm BNC connector is described in standards MIL-STD-348A or MIL-C-39012 (IEC 169-8). The conventional 50-ohm BNC connector has a connector housing and a dielectric insert disposed therein. The dielectric insert has an engagement end that is configured to interface with a coupling connector. An electrical contact extends through a center of the dielectric insert and has a socket located at the engagement end of the dielectric insert. The socket is configured to mate with a mating pin contact of the coupling connector. In the conventional. 50-ohm BNC connector, the dielectric insert has a neck that immediately surrounds the socket of the electrical contact in order to provide mechanical support for the socket. The dielectric insert in the 50-ohm BNC connector may be shaped at portions other than the engagement end to provide a desired impedance for the connector. For example, a rear end of the dielectric insert or a mid-portion located between the engagement and rear ends may be shaped with respect to the connector housing and the electrical contact to provide an air dielectric to achieve a desired impedance.
Conventional 75-ohm BNC connectors may also include a neck that immediately surrounds the socket of the electrical contact in order to provide mechanical support. Also, the engagement end of other conventional 75-ohm connectors may have a planar surface that extends perpendicular to an axis of the electrical contact. Similar to the 50-ohm BNC connector, other portions of the dielectric insert beside the engagement end may be shaped to provide ail air dielectric to achieve the desired impedance.
However, existing methods for controlling impedance in electrical connectors, such as the methods described above with respect to 50-ohm and 75-ohm BNC connectors, have limited effectiveness in, obtaining a desired impedance for the electrical connectors at the engagement end/interface. Accordingly, there is, a need for electrical connectors having a desired impedance and for methods of controlling impedance in electrical connectors.